An improved method for using Doppler-broadened positron annihilation spectroscopy for the study of the electronic properties of materials

The microspectrum data collection method is shown to improve the reproducibility of the Doppler PAS technique by reducing non-statistical counting errors. The raw data are then deconvoluted to remove the effects of instrumental broadening. This procedure is used to calculate the Fermi energy level in high-purity polycrystals of Cu and Al. Using a best-fit parabola superimposed on a gaussian we find Esub(f)(Cu) = 7.8 eV and Esub(f)(Al) = 12.4 eV. These values are compared with both theoretical values and corresponding values calculated from the angular correlation PAS technique. (author)